A conventional vehicle seat includes a backrest, a seat and a headrest, which is connected to the top of the backrest. The headrest has two positioning rods extending into the backrest in which an engaging device is received which engages with notches defined in each of the two positioning rods so that users may pull the headrest to a desired height by operating the engaging device. The distance between the two positioning rods is fixed so that the headrest cannot be used with a seat which is not designed for the specific headrest, for example a seat of a different model vehicle.
The present invention intends to provide a headrest wherein the distance between the two positioning rods of the headrest can be adjusted to accommodate different engaging devices.